Age Hardening Ni-Cr-Co Nimonic 90 , Creep Resistance High Strength Alloys

Nimonic 90 Precipitation Hardenable Ni-Cr-Co Alloy with High Strength

Introduction

Nimonic 90 is a precipitation-hardenable nickel-chromium-cobalt alloy having high stress-rupture strength and creep resistance at temperatures to about 1700°F (920°C). Nimonic 90 also has good resistance to high-temperature corrosion and oxidation. Nimonic 90 is used for blades and discs in gas turbines, hot-working tools, and springs.

Characters

High stress rupture strength and high creep resistance at high temperatures

Good resistance to high-temperature corrosion and oxidation

Age-hardenable

High temperature dynamic applications

Application

The alloy is used for turbine blades, discs, forgings, ring sections and hot-working tools. Also used to make Aerospace fasteners.

Chemical composition

C≤0.13, Cr=18.00~21.00, Co=15.00~21.00, Al=1.00~2.00, Ti=2.00~3.00, Fe≤1.50, Zr=≤0.0150, B≤0.020, Si≤0.80, Mn≤0.40, S≤0.015, P≤0.020, Cu≤0.200, Ni=Remainder

Typical Mechanical Properties – Spring Applications
Solution Treated
Heat Treatment: 1922 - 2012°F (1050 - 1100°C) + WQ
Tensile Strength: 157 ksi max; (1080 MPa) max
Spring Temper
Heat Treatment: As supplied condition.
Tensile Strength: 189 - 223 ksi; (1300-1540 MPa)

Spring Temper + Aged
Heat Treatment: After spring coiling. Age: 1202°F (650°C) for 4 hours. Alternatively, Age at 1112°F(600°C) for 16 hours and air cool.
Tensile Strength: 189 – 260 ksi; (1300 – 1800 MPa)
Suggested Operating Conditions: Optimum stress and low relaxation at temperatures up to 700°F (371°C)

Solution Treated + Aged
Heat Treatment: After spring coiling: Solution Heat Treat: 1976°F (1080°C) followed by rapid cooling + Age at 1382°F (750°C​) for 4 hours and air cool. Alternatively, Age at 1292°F (700°C) for 16 hours and air cool
Tensile Strength: 145 - 203 ksi; (1080 - 1400 MPa)
Suggested Operating Conditions: Optimum resistance to relaxation at temperatures up to 1112°F (600°C)